At 04:54 PM 12/2/97 +0100, you wrote:
>I have a good bargain for buying a beautiful corsair ll with ext vfo or
>a splendid omni 6. of course it is not the same price (the omni is 100%
>more expensive) but I really hesitate between these two rigs. I'm afraid
>to be desapointed with the corsair 2 sensitivity on ten meters.
>I'd like to get some comments from ten tec users. Thanks.
>
>73's de Marc, f6iiv.
>=20
I apologize for the bandwidth, but my direct reply to Marc failed. I hope
he will be able to read this.
73 es tnx - John, W4AU
Marc -
Here is a copy of a comparison I wrote about one year ago just after I had
gotten my new Omni VI. I hope you find it useful.
73 - John, W4AU
**************************
As promised a while ago, I have written this look at the Omni VI is from
the perspective of a Corsair II user (and fan!) for hams on the TenTec
reflector to read. This purely subjective information comes from using my
new Omni VI for a grand total of five weeks after having a Corsair II in
constant use for Dxing, contesting, and general all around ham radio for
over 3 years. I should add that I operate CW about 99% of the time.
Similarities:
1. Both made by TenTec; this fact speaks for itself and conveys the idea of
quality construction and legendary service.
2. The two rigs use the same filters in the 6.3MHz IF; e.g., you can use
your Corsair II filters in the Omni VI. I am also using my TenTec 961 power
supply that came with the Corsair II; it works fine.
3. The two rigs "sound" alike when listening to CW; this may be a function
of using the same IF filters and is hard for me to define, but that's the
only way I know how to say it. I should add that I mostly use the 500Hz
filter for CW.
4. Both rigs have internal keyers that I can't comment on; I use an
external keyer.
Differences I have noticed:
1. When you are in the CW mode, the CW sidetone is always on the "upper"
side of the zero beat frequency on the Omni VI; on the Corsair II it is on
the upper side on 30 Meters and below and on the lower side above 30 Meters.
2. The noise blanker on the Omni VI works. I never saw any effect of the
Corsair II's noise blanker on any interference I experienced. I don't think
it was just my rig either; I have two friends with Corsair II's who have
had similar experiences.
3. The CW sidetone frequency and the transmit offset from the receiving
frequency are identical on the Omni VI and can be changed, but if your
transmit offset gets far from 700 Hz the CW bandpass filters won't work
right because they are centered on 700 Hz (you can compensate with the
passband tuning, though). On the Corsair II the transmit offset is fixed
and you can adjust the sidetone frequency by itself. The sidetone quality
on the Omni VI is much nicer and easier on the ears.
4. The top-mounted speaker and/or better audio output make the Omni VI
sound better than the Corsair II on SSB and CW; the audio seems clearer and
stronger. I almost always used the speaker in the 961 power supply with the
Corsair II; now the power supply is tucked away out of sight.
5. The passband tuning in the Omni VI just works better than the one on
the Corsair II. It seems to cut out interfering signals cleanly with a
minimum of distortion both on CW and SSB.
Operating Impressions:=20
When I first sat down in front of the Omni VI I noticed two things: the
frequency display is larger and reads to the 0.01 KHz, and the tuning knob
feels smoother and, well, just nicer. The tuning rate on the Omni VI can be
set from 0.85 to 5.12 KHz per revolution, but the fastest rate, 5.1 KHz per
revolution, is much slower than the Corsair II's 17 KHz per revolution.
After a short adjustment period for my fingers, I am now used to and like
the slower tuning rate on the Omni VI better.
The Omni VI makes use of some coaxial control knobs rather than having all
single function knobs like the Corsair II. However, usually only one of the
coaxial knobs' functions is used frequently, and the other is "set and
forget". For example, AF and RF gain are ganged, as are drive and mic gain.
In case you didn't guess, I'm not a fan of coaxial knobs=85
The receiver in the Omni VI is HOT! At first I thought that the Corsair II
was quieter, but then I realized that the Omni VI's receiver is more
sensitive and that I was hearing more signal, too. The AF gain control
seems more sensitive in the Omni VI than in the Corsair II; with head
phones on the control goes from very quiet to very loud in only about 90
degrees of rotation. It would be nicer to have a more gradual, linear
"volume control". I use both transceivers with their RF gains set from
about the 1 to 3 o'clock position under normal conditions. I rarely have
the RF gain "cranked up" all the way.
The Omni VI is definitely more selective than the Corsair II for CW
contest-type operating with lots of adjacent strong signals - even without
using the 500 Hz filter in the 9 MHz IF. With the 500 Hz, 9 MHz filter, the
performance is awesome; you can work very close to strong signals and not
even be bothered by interference. I am using exactly the same 6.3 MHz
filters in my Omni VI that I had in my Corsair II. I have experienced
absolutely no ringing or signal deterioration using the 500 Hz or 250 Hz
filters either with or without the addition of the 9 MHz filter.
Things I miss:
1. The big one - being able to listen to two frequencies at once and vary
their relative volume like I can with the Corsair II and its external VFO.
But with the A/B split on the Omni VI you can alternately listen to two
frequencies, even on different bands, just by holding and releasing the REV
button, very nice.
2. With the Corsair II, I used its QSK output jack to key my venerable
Drake L-4B amplifier through an external QSK switching box that I built
using Jennings vacuum relays. The Omni VI does not have a direct QSK output
analogous to the Corsair II's, so I have to use the T/R relay output and
run my amp essentially non-QSK. There may be a possibility to use the QSK
out and enable jacks on the Omni VI, which are designed for use with the
TenTec amps to drive my QSK box; I'm looking into that possibility.
Omni VI features I now can't live without:
1. Moving around the bands with direct frequency entry and switching from
band to band and always returning to the same frequency-filter-mode on a=
band.
2. Having a computer interface to the rig so that my contesting and logging
programs can automatically control the rig's frequency and vice-versa.
3. The additional selectivity of that 500Hz filter in the 9MHz IF.
4. The DSP notch filter is "magic" on SSB. You just hit the button an
tuner-uppers and heterodynes simply vanish.
Regrets:
My only regret is that I waited so long to get the Omni VI!!
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